etymology vs whence it came

etymology

noun
  • The study of the historical development of languages, particularly as manifested in individual words. 

  • An account of the origin and historical development of a word as presented in a dictionary or the like. 

  • The direct origin of a name, as in who someone was named after. 

  • The origin and historical development of a word; the derivation. 

whence it came

How often have the words etymology and whence it came occurred in a corpus of books? (source: Google Ngram Viewer )